The invention described herein concerns key safes into which a door key may be placed and securely locked. Conventional key safes employ key locks and hinged doors on removable key drawers. The object of this invention is to provide an easily fabricated, structurely sound key safe which may be securely attached to a door and which may be opened by any number of designated persons without the necessity of providing each person with a key for a key safe.
A collection of devices of the type known in the prior art is found in the Official United States Patent Office Classification of Patents, particularly in Class 70, subclasses 63, 58 and 57. Examples of such devices are found in U.S. Pat. Nos.: 1,613,813, 2,512,028, 2,911,814, 3,204,436, 3,236,075, 3,347,069, 3,436,937, 3,636,742 and 3,695,067.
A prior invention described in U.S. Pat. No. 3,236,075 employs a key lock to fasten a protective housing to back plate on which a door key may be fastened. A rotatable projection on the key lock engages the back plate and maintains the housing in position. The key safe in this invention is attached to a U-shaped bracket which may be fitted on the margin of a door. In another configuration, the device is equipped with a U-bolt which may be clamped about a door knob by inserting a pin through the U-bolt and thereby pinning the U-bolt to the key safe at a point where the U-bolt passes through the key safe.
In the known invention described in U.S. Pat. No. 3,347,069, a security container is designed with a hinged lid which may be locked in a closed position by means of a built-in recodeable code lock or a built-in key lock.
In conventional key safe apparatus, a door key may be stored in a box-shaped drawer which may be inserted into a receptacle box. The drawer is locked in place by means of a key lock. The receptacle box is equipped with a U-shaped bracket to engage a margin of a door.
A need exists for an easily and cheaply fabricated key safe of great structural strength. A need also exists for a key safe which may be conveniently opened by any number of designated persons without the necessity of providing each person with a key for the key safe. Such a key safe must be equipped with means to firmly fasten the safe to a door so that the safe cannot be removed by unauthorized parties.